Few-layer alpha-germanium crystal, their preparation processes and uses therof

A technology of crystal and carbon number, applied in the field of α-germanium crystal in sheet form, can solve problems such as efficiency limitation and achieve the effect of less material amount

CN112218827AInactive Publication Date: 2021-01-12NANOINNOVA TECH SL +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2021-01-12
Estimated Expiration
Not applicable · inactive patent

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Abstract

The present invention relates to [alpha]-germanium crystals having a laminar morphology, the crystal comprising one or more stacked nanosheets of germanium, and to two methods for obtaining said crystals. The invention also provides a powder comprising the [alpha]-germanium crystals of the invention, dispersions comprising the [alpha]-germanium crystal of the invention or the powder of the invention, as well as an ink comprising said dispersions.
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Description

technical field

[0001] The present invention is included in the field of germanium crystals. In particular, the present invention relates to alpha-germanium crystals in the form of flakes. Background technique

[0002] The current application of semiconductor materials containing elements from group 14 of the periodic table, such as silicon or germanium, in electronic devices has led to an exponential growth of interest surrounding materials derived from these elements. These materials not only have applications in the field of transistors, but both silicon and germanium constitute the photovoltaic industry [A. Polman et al., Science, 2016, 15, Vol. 352, 6283, p. 4424] and the photodetector industry [Nam JH, Opt.Express. 2015 Jun 15; 23(12):1581623, US4725870A]. However, despite their excellent performance in the aforementioned fields, considering that they are semiconductors, their efficiency in optoelectronic applications may sometimes be limited due to their band-gap. ...

Examples

Embodiment

[0079] Two methods for obtaining the plate-shaped α-germanium crystals of the present invention are described.

[0080] 1. Wet grinding:

[0081] 200 mg of commercial polycrystalline alpha-germanium crystals (SmartElements or Aldrich, 99.999% pure) were placed in a steel pebble bed reactor with two-thirds of the reactor volume free. Add 1 ml mixture of water and isopropanol (2-propanol / H 2 O, the volume ratio is 4:1), and milled in the reactor at 3000rpm for 60min. The α-germanium powder obtained after grinding was vacuum-dried at 60 °C for 12 h and stored in an Ar atmosphere to prevent possible oxidation.

[0082] 2. Ultrasound:

[0083] Commercial polycrystalline α-germanium crystals (Smart-Elements or Aldrich, 99.999% pure) with an initial concentration equal to 20 g / L were prepared in a mixture of water and isopropanol (2-propanol / H 2 O, a dispersion in a volume ratio of 4:1). The dispersion was sonicated with an ultrasonic head at 400 W and 24 kHz for 45 min. The re...